1. 07 1月, 2008 1 次提交
    • L
      Revert "scsi: revert "[SCSI] Get rid of scsi_cmnd->done"" · 7b3d9545
      Linus Torvalds 提交于
      This reverts commit ac40532e, which gets
      us back the original cleanup of 6f5391c2.
      
      It turns out that the bug that was triggered by that commit was
      apparently not actually triggered by that commit at all, and just the
      testing conditions had changed enough to make it appear to be due to it.
      
      The real problem seems to have been found by Peter Osterlund:
      
        "pktcdvd sets it [block device size] when opening the /dev/pktcdvd
         device, but when the drive is later opened as /dev/scd0, there is
         nothing that sets it back.  (Btw, 40944 is possible if the disk is a
         CDRW that was formatted with "cdrwtool -m 10236".)
      
         The problem is that pktcdvd opens the cd device in non-blocking mode
         when pktsetup is run, and doesn't close it again until pktsetup -d is
         run.  The effect is that if you meanwhile open the cd device,
         blkdev.c:do_open() doesn't call bd_set_size() because
         bdev->bd_openers is non-zero."
      
      In particular, to repeat the bug (regardless of whether commit
      6f5391c2 is applied or not):
      
        " 1. Start with an empty drive.
          2. pktsetup 0 /dev/scd0
          3. Insert a CD containing an isofs filesystem.
          4. mount /dev/pktcdvd/0 /mnt/tmp
          5. umount /mnt/tmp
          6. Press the eject button.
          7. Insert a DVD containing a non-writable filesystem.
          8. mount /dev/scd0 /mnt/tmp
          9. find /mnt/tmp -type f -print0 | xargs -0 sha1sum >/dev/null
          10. If the DVD contains data beyond the physical size of a CD, you
              get I/O errors in the terminal, and dmesg reports lots of
              "attempt to access beyond end of device" errors."
      
      which in turn is because the nested open after the media change won't
      cause the size to be set properly (because the original open still holds
      the block device, and we only do the bd_set_size() when we don't have
      other people holding the device open).
      
      The proper fix for that is probably to just do something like
      
      	bdev->bd_inode->i_size = (loff_t)get_capacity(disk)<<9;
      
      in fs/block_dev.c:do_open() even for the cases where we're not the
      original opener (but *not* call bd_set_size(), since that will also
      change the block size of the device).
      
      Cc: Peter Osterlund <petero2@telia.com>
      Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
      Cc: Matthew Wilcox <matthew@wil.cx>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      7b3d9545
  2. 05 1月, 2008 2 次提交
  3. 04 1月, 2008 21 次提交
  4. 03 1月, 2008 12 次提交
  5. 02 1月, 2008 4 次提交